Suspending membranes have been used in the past in lieu of resilient inserts and filling material to hold and cushion objects within a container. Before my inventions disclosed herein and in U.S. Pat. Nos. 4,852,743 and No. 4,923,065, this type of packing was exclusively indicated for light and delicate objects such as horological parts as disclosed in U.S. Pat. No. 4,491,225 Baillod. The resilient stretchability of the membrane itself was thought to provide the bulk of the shock-absorbing process. This is particularly illustrated in U.S. Pat. No. 2,134,908 Copeman which teaches the use of elastic membranes which are stretched over opposite sides of a fragile object such as an egg to provide cushioning against loads incident upon the parallel planes of the unstretched membrane. No cushioning against lateral movements of the object along directions generally parallel to the planes of the membrane was provided by the membranes. That type of movement was restricted either by the edges of the apertures over which the membranes were stretched or by resilient separators made of various materials. In U.S. Pat. No. 4,491,225 the object is supported above a void by a first horizontal membrane, then covered by a second membrane which is joined to the first membrane along its periphery. The joined edges of the two membranes are supported midway between the top and bottom internal surfaces of the container. The bottom membrane acts as an hammock. That role is taken by the top surface when the container is laid upside down. The elasticity of the membranes provide cushioning against vertical loads. Since the membranes are stretched over the supported object and partially wrapped around some of its convex extremities, lateral impacts are also absorbed by the elastic deformation of the membranes. Japanese Patent No. 135,796 Kondou reveals the same hammock-type suspension technique, but instead of joining the edges of the membrane, it teaches the stretching and mounting of the membranes over two symmetrical halves of an empty container which are then brought together like clam shells to hold the delicate object suspended therebetween.
Due to the elastic quality of the membranes, it was thought that heavy objects could not benefit from this type of packaging as their weight would progressively deform the underlying membrane to a point where the space between the object and the bottom of the container would not be sufficient to absorb expected vertical shocks, or to the extreme situation where the object would come in contact with the floor of the container. My inventions improve the membrane packing techniques of the prior art to a point where they can be applied to the packing of relatively heavy objects.